Railway signal system



Jan. 6, 1931. l s. MCFARLAND 1,787,752

RAILWAY SIGNAL SYSTEM Original Filed Aug- 6. 1927 3 Sheets-Sheet l www jim/Weg,

Jan. 6, 1931. s, E, MCFARLAND 1,787,752

RAILWAY SIGNAL SYSTEM Original Filed Aug. 6, 1927 5 Sheets-Sheet 2 I 12e/2 for',

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Jan. 6, 1931. S. E. MCFARLAND t 1,787,752

RAILWAY SIGNAL SYSTEM Original Filed Aug. 6, 1927 5 Sheets-Sheet 3 Patented Jan. 6, 1931 'UNITEDSTATES .PATENT orales SAMUEL E. 'MCFARLANn or SOUTHGATE, kCALIFORNIA RAILWAY SIGNAL SYSTEM Application rfiled. August 6, 1927, Serial No. 211,016. Renewed MayQS, 1930.

This invention has reference particularly to that class of railway Signal systems 'wherein a Signal is actuated by orunder control. of a passing train.- The actuated* signal itself may be of any type or kind and perform any desiredj signaling service; but for the purpose of explaining the present invention it may be assumed, but without limitation, that the signal is of the crossing signal type adapted to warnpersons at crossings of the approach of trains. The invention is not concerned with the nature or ydetails of the signal itself, but with the nature and characteristics of a signal actuating or control-` ling system.

Although there are' many minor objects and corresponding accomplishments of the invention, as will appear fromthe following detailed description, it may besa'id thatk genprovide a signal system that is simple in construction and operation, 'not liable to disorder and therefore trustworthy and sure inaction, in which the parts. that are directly I actuated from the rail by the weight of a passing train, are mechanical in theirnature and are simple and rugged in construction and in which the electrical parts of the system can be removed from the track. In my system they parts located at or upon the track and at or near the ground are purely mechan-v ical in their nature and of such a construction that water, mud, etc., cannot interferewith their action. These mechanical parts actuate the electrical parts of the system which may be (but not necessarily) located at an elevation above the ground and canV therefore be protected effectively enough that high voltage, Such as is used on trolley lines, may be used in the electric circuits.

The invention also contemplates improved.

erally the mainy object of the invention is to v line 4 4; of Fig. 2;

Fig. 5 is a plan of the actuating relay; Y v Fig.4 6 is a vertical cross section showing the track instrument; and f Fig. 7 is a section on line'7-7 of Fig. 6.

Referring first to'Figs'. G and 7 I first exi plain thetrackinstrumentinits'now preferred form. In Fig. 6 the numeral 10 may designate the track rail, the usual rail supporting ties or sleepers being indicated at 11. The track instrumentl will preferably be set in a suitable box or'other casing 12 mounted upon a foundation 13 which. is'independent of the rail supports l1; sol that when the rail is depressed bythe weight of a passing train the track instrument will not be correspondingly depressed. It is the relative motionbetween the rail and the track instrument that I make use of in my system for actuating the control v relays.

Within the box of the track instrument in its preferred form there is a rotative shaft 14 mounted in a suitable bearing,las for instance a bearing 15 formed in one side of boX 12. The Outer end of this shaft has a rail engaging arm 16, the end of this arm being notched as shown at 17, or otherwise suitably, s o as to Aengagethe upper and lower surfaces of the rail flange and thus to cause verticaly swinging movement of arm 16 with the vertical movement of the rail. IVhen the rail is depressed the arml swings around in the direction indicated by the arrow innFig. '6 and turns shaft lain that direction. Mounted on shaft 14; and turning with it are two plates 18 and 19. Between these two plates there are two friction disks 2O and between the two friction disks liesthe hub 21 of a depending ico of the upper end of lever 23 towards the 'left' in Fig. 6, thelimit of that movement occurring when lever 22 brings up against s`top21.

Friction plate 19 is pressedtoward friction plate 18 by the spring 25 adjustable by nut 26; so that the friction pressure on hub 21 is adjustable. Arm 22 is thus frictiona'lly rotatively connected with arm 16; and the friction is adjusted at such pressure vthat it is Asufficient to move arm 22 against thefresistance of the apparatus parts whichare connected to and voperated by lever 23.; but the friction at hub 21 is insuficient'to cause further movement ofarm 22 when arm l22 brings Aup againststop 215. For ,instance when rail train the action will be to move lever 23to the left in Fig. 6. The parts are so designed and proportioned that the minimum rail .depression willalways be sufficient to move arm 22 up against stopk 21?) g so that, after arm 22 has gone through its yfull motion,further depression of the rail will cause a slippage of On the back travel-the the friction joint. :upward movement of rail 10 and the movement of arm 22 toward the leit in Fig. 6 the arm 22 will then always bring up vagainst low arm 16 to move on'up with the rail. Stop thus limits the normal position of arm 22 and also the vnormal position of lever 23; and the amount of movement possible `to arm 22 is the movement from the position shown in Fig. 6 to a position where it brings up against stop 215. The arm 22 and lever 23 vbeing thus limited in vtheir movements, they will always be moved through delinite movements by the depression ofrail 10, the friction taking` care of the over movement of rail 10. .Also, as will .now readily be seen, theV frictional slippage takes care of anyV gradual or permanent change of position of rail 10, or due to tamping up.-

Connected with the -upper end of lever 23 there is a mechanical connection element preferably in the form of a Bowden wire 31 which 'extends to the relay for causing its actuation,

the relay being actuatedby a .pull upon the wire; Y Y

The starting or initial actuating relay is shown in Fig. 5 and designated asa whole by the letter l..V It consists essentially in a' snap action switch which may7 be formed in the simple manner shown. A pivot arm 35 is adjustably connected to the Bowden wire `31.

due to settling A turnbuckle 36 may be used for adjustment. An adjustable spring 37 holds arm 35 in its normal position, the position shown in Fig. 5. A pivoted switch arm 38 is connected to arm 35 through the medium of a spring 39; the relative positions of the two arms being such that when arm 35 is in vits normal position the tension of the spring .39 will hold switch arm 38 lin `its illustrated normal position against the stop 40. Movement of arm 35 in the d1- rection indicated -bythefarrow, caused by a pull upon Bowden wire 31, will, after a ce1'- 'tain' amount of movement of arm 35, snap switch arm 38 over against theadjustable contact 41. Arm 35 will remain in the second mentioned position justsolong as thelpull is continued to be exerted .on wire 31-just so long asthe track instrument remains Vactuated by adepression of the'r'ail. As soon Vas the rail rises andthe pull on wire 31 ceases, spring 37 will pullthe parts back to their normal positions, causing switch arm 38 to lbreak v.contact with the contact 41`1andto go back to its normalaposition-/as shown in Fig. 5. So far as the operation of my system is concerned the 10 is moved down by the weight of a passing engagement lof switch arrn'38 with contact 41 maybe either momentary or ofV some duratio-n, as will be understood from what follows.

The release relay. is vshown in Fig. 2. .A pivoted switch arm 45 is adapted to swlngibetween two positions in which' it contacts with Veither of t'headjustable*contacts 46 and 47.

Tension spring 48 connects vswitch arm 45 -with a slider 49 which is shown 1in detail in Fig. 3. Thisslider ismountedon a slide `bar 50 and may preferably be constructed vas Y Y shown in Fig. 3. iblock of insulating mate- 's'top -30 and the friction will again slip to alf rial 51 rests on slide bar 50 and has strap 52 which passes around the bar. A spring attachment plate 53 is mounted on the upper side of block 51, spring 48 being'attac'hed to this plate. Slider 49, so constructed, is slidable upon and with reference to slide bar '50;

- but lthe tension of spring 48 tends rat all times to bind the slider 49 on-bar 50 so that when `ba.r.50 is moved the slider will move with the 'bar, although the slider can be moved on the vbar without-the barmoving at all.

Slide bar 50 is pivot-ally connectedat 55 at wire 31 is connected to arm 58 through the medium of the adjusting turn-buckle 60. Also arm 58 has a dash pot 61 connected to it, the dash pot acting to allow relatively free movement of arm `58 in the direction indicated by the arrows, but retarding movement of the arm and of bell crank lever 57 in the opposite direction. K

` VAll the parts'so far described are mounted upon a suitable base or in a suitable box or other enclosure V62 so as to be protected from weather. Also mountedv within the enclosure is asolenoid magnet 6.3 which when energized l" lowerl gui-de blocks 68 and` 69, as shownin lll detail in Fig. 4; this forni of mounting allowing freedomA for the slight oscillation of the pivot end at 55.

Referring now more particularly to Figl I here illustrate Vdiagrammatically a railroad track T with its rails It. In a typical installation two or more track instruments C may be used. For instance supposing that the direction of train travel is towards the left in Fig. 1, one track instrument C will be located to the right at a suitable distance from the crossing and another track instrument C-l will be located at a suitable distance to the left of the crossing. Vilhen a train approaches the crossing from the right it 'depresses the rail at track instrument C and actuates that instrument to pull upon the wire 31 and to actuate the relay R in the manner before described. Switch arm 38 of this relay is connected by wire 70 to ground as illustrated. From contact 41 a wire 71 connects to one side or" solenoid 63 of release relay It-1, thel other side of the solenoid being connected by wire 72 to one side of signal S. The other side oi signal S is connected by wire 73 to the current supply lwire 74, which wire connects directly into contact 46 of relay R-1. It will be understood that in describing the circuits in this system I am assuming the current is being` used from a trolley circuit; and that therefore in thisl specific illustration one side of the circuit will come from the trolley wire or trolley feed system while the other side or' the circuit will be formed by ground. tions bothsi-des of the eed circuit in my system may be formed by wires orother conductors.

The other contact 47 of relay R-l is connected by wire 75 to ground, switch arm 45 pf relay R-l is connected by wire 76 to wire When the relay switch at- R is closed, solenoid 63 is then energized in a circuit as follows from wire 74 through contact 46, switchy arm 45, wire 76, wire 72, solenoid 63, wire l 71, contact 41, switch'arm 38 and wire 70 to ground. This energization causes the solenoid to move slider 49 towards the left far enough that the-spring 48 acts to snap switch arm over to engagement with contactr 47. Immediately this occurs current then ilows from wire 74'through wire 7 3 to In other installa`V and through'the signal S, thence through wire72, wire 7 6, switch-arm 45, contact 47 and wire 7 5 to ground. I inthe meantime relay R has not-gone back to normal position current will ycontinue to flow also through wire 72 and through solenoid 63 and on to ground through relay It. But as soon as .relay R goes back to its normal position, which it does 'as Ysoon as the rail at track instrument() rises (as soon as the train has passed that point) then current through the solenoid 63 is cut off; but the switch arm 45 of relayy R 1 remains in its position in engagement with contact 47 until track instrument C-l is actuated by depression of the railat its location. When the head end of the train reaches the location of track instrument C-l and the rail there is depressed, that track instrument operates to pull upon its Bowden wire 31 and movebell crank lever 57 in the-direction indicated by the arrows in Y This movement of the bell crank lever moves the slide bar 5G toward the left through slider 49. Slider 49 has been moved up against block 68 by the action of the solenoid and can move no further to the left. Consequently when slide bar 50 is moved to the leftit moves through slider 49. The parts having been moved to the described position, they remain in that positionuntil after the last truck of the-train has passed the location of the track instrument @-1, when the parts are slowly returned to their normal positionby. the action of spring 59,-dash pot 61 regulating the speed of this return. The useful function ofdash pot 61 is to prevent the return of the parts of relay R-l to normal position immediately aftera truck has passed over the location of track instrument @-1, thus keeping the relay R-1 in its actuated position during the intervals between the passage of successive trucks over the location of track instrument C-1, and preventing a multiplicity of successive actuations of relay R-1 by the passage of successive trucks. When the last truck has passed Vover the location of. track instrument C-1, then spring 59 Amoves the parts or relay R-l back to the normal position shown in Fig. 2, snapping the switch arm 45 back to its normal position and cutting off current from signal S. A

It it is desired to prevent the actuation of 'the signal system by train traveling in the opposite direction on track T (for instance toward the right in Fig. 1) then a third track instrument C-2 may be installed at a suitablek distance to the left of track instrument C. rIhis track instrument C-2 will be, in structure and-operation, the same as the trackinstrument before described. Its Bowden wire 31a will extend to the track instrument@ and there connect with an arm 30 pivoted at 81 and engaging the friction plate 19 in such `a manner that a pull upon wire Slafwill cause friction plate 19 to bemoved back againstl the pressure ot spring 25 and relieve the frictional pressure oi disks 20 upon hub 2l oi arm 22. The track instrument @-2 being located a proper distance to theleft of track instrument @it a train should ilavel toward the right upon track it would irst depress the rail at the location ot track instrument 0 2 and exert a pull upon wirela to relieve the friction ot track instrument C. Then as the Erst truck of that traink proceeds onward toward -trackinstrument C, and asthe rail at the location of C is being depressed, theY rail at the location of C-2 will remain depressed to some extent,

depression of the rail at the location of (lV will not act to operate the arm 22 of track instrument C and therefore will not act to actuaterelay R. This provision prevents any train which is traveling Vin such a direction that it passes track instrument Gatter passing track instrument C-l from setting the signal system into action.

I have given a specic description of my now preferred form of system and devices; but it will be understood vthat many variations, in detail and in arrangement, may be made without exceeding the invention. Other detail designs, forms ot parts, etc., will readily occur to those skilled in the art; for instance the forms and arrangements ot the lever. arms, and the ,engagement or connection of arm 16 with the rail, which may be effected in any suitable manner. Likewise the relative arrangements of the elements of the system may be varied to suit any given requirements. Although I have particularly mentioned the fact that the relays may be situated at a distance from -the track instrument, they are not necessarily so placed. They maybe placed close to their respective track instruments or even in the same boX with them, eliminating the necessity ot' a long Bowden wire or other mechanical connection. It the Bowden wire is thus made short enough, or other short mechanical connection be used, it becomes an element through which a push can be communicated as well as apull. In that case, the operative connection 3l to lever' of relay B1 will, when the track at C1 is depressec., vmove the, lever to actuated position, and then move it slowly i back to normal position as the rail rises after a train has passed. ln that case the dash pot 6l and spring 59- might be dispensed with.

'I claim:

l. A railway signal system adapted to be actuated by rail depression, embodying two track instruments adapted to be mechanically actuated by local rail depression, an initial actuating relay mechanically connected with one-instrument and comprising a switch, an-

other relay mechanically connected with the action and lea-ving it inV other instrument and: comprising a switch, mechanical switch operating means actuated 'from said instrument, and electro-magnetic `switch operating means; a signal, vand circuits by which the 'electro-magnetic means is energized through Vthe switch ot the first mentionedrelay and the signal is energized through the switch ot' the second mentioned relay. o

2. A railway signal system adapted to be actuated by rail depression, embodying two track instruments adaptedto be mechanically actuated by local rail depression, an initial actuating relay mechanically connected with one instrument and comprising a snap-action switch, another relay vmechanism comprising ai snap-action switch, a slider whose movement actuates the switch, electro-magnetic means for moving the slider in` one direction, mechanical means for moving the slider in the opposite direction, said mechanical means being mechanically connected with the other track instrument; a signal, and circuits leadingthrough the iirst mentioned switch, the electro-magnetic means and the signal, and through the second mentioned switch and the signal.

3. In a signa-l system, the combination of two track instruments, each having a frame adaptedto be supported independently of a rail, an actuating arm movable on the frame and connectible with the rail, an actuated arm yieldingly connected with the actuating arm and having a limited movement with respect to the frame, means provided on one ot the instruments for releasing the yielding connection between its actuating and actuated arms, and the actuated arm ot the other instrument being connected to said means to cause its release. A y

4. In a signal system, a relay device embodying a double throw switch -with a pivoted switch arm, a slide bar adapted to move ri-n a direction transverse of the switch arm, a slider on the slide bar and movable on and with relation thereto, a spring connecting the slider withv the switch arm, means tor actuating the slide bar, and independent means tor moving the slider on and with relation to the slide bar.

5. Ina signal system, a relay device embodying a double-throw switch with a pivoted switch arm, a slide bar adapted to move in a direction transverse of the switch arm, a slider on the slide bar and movable kon and with relation thereto, a spring connecting the' slider with the switch arm, mechanical means for moving the slide bar, and electromagnetic means for moving the slider independently of the slide bar. 6. In a signal system, a relay device embodying a double-throw switch wi th a pivoted switch arm, a slide bar adapted to move in a direction transverse ot the lswitch arm, a slider on the slide bar and movable on lUO and with relation thereto, a spring connecting the slider with the switch arm, mechanical means for moving the slide bar, and electro-magnetic means for moving the slider independently'of the slide bar, said means embodying a pivoted lever moved in one direction by a spring, and a dash pot allowing free movement of the lever in the other v direction but retarding the movement of the lever by the spring. Y

7. In a railway system, a track instrument comprising a frame adapted to be supported independently of a rail, an actuating arm movable on the frame and connectible with the rail, an actuated arm yieldingly connected with the actuating arm and having a i limited movement with respect to the frame,

and automatic means for releasing the yields ing connection between the actuating and actuated arms.

8.y yA railway system adapted to be actuated by rail depression, embodying a track instrument adapted to be mechanically actuated by local rail depression, an initialA actuating relay mechanically connected with said instrument and comprising a switch, another relay comprising a switch, electro-magnetic switch operating means for said last mentioned relay, a signal, and circuits by which the electro-magnetic means is energized through the switch of the first mentioned relay andthe signal is energized through the second mentioned relay. l

9. A railway system adapted tobe actuated by rail depression, embodying a track instrument adapted to be mechanically actu-f ated by local rail depression, an initial actu ating relay mechanically connected with said instrument and comprising a switch, another relay comprising a switch, electro-magnetic switch operatingmeans for said last mentioned relay, a signal, circuits by whichthe electroemagnetic means is energized through the switch of the first mentioned relay and Y the signal is energized through the second mentioned relay and automatic means vforV actuating the switch of the second mentioned relay to de-energize the signal. Y

In witness that I claim the foregoing I have hereunto subscribed by name this 14th .day of June, 1927.

SAMUEL E. MGFARLAND. 

